Pressing assembly and method of loading a press

ABSTRACT

A pressing assembly ( 10 ) includes a press ( 12 ) being moveable from an open configuration to an operable configuration to compress an object ( 16 ). A loader ( 14 ) is also provided having one or more first pushers ( 42 ) moveable into a region within the press ( 12 ) to load the object ( 16 ) into a pressing zone within the press ( 12 ). The arrangement is such that the or each pusher ( 42 ) is clear of the pressing zone once the press ( 12 ) is in the operable configuration. The or each pusher ( 42 ) may be provided on a reciprocable pusher assembly ( 36 ) which is moveable in a forward and a reverse direction. In the forward direction of the reciprocable pusher assembly, the first pusher ( 42 ) pushes the object into a pressing zone in the press. A second pusher ( 44 ) is also moveable with the pusher assembly ( 36 ) for ejecting another of said objects from the pressing zone on forward movement of the pusher assembly ( 36 ) wherein, in the reverse direction of the pusher assembly, the second pusher ( 44 ) is moveable relative to the pusher assembly ( 36 ) to retract beyond the object loaded into the pressing zone.

FIELD OF THE INVENTION

The present invention relates to a pressing assembly. In particular,although not exclusively, the invention relates to a pressing assemblywhich includes a loading/unloading means to convey bales into acolumn-type press. However, the invention is not restricted in its usefor conveying bales into a press and may indeed be adapted or applied toconvey any type of object into any type of press.

BACKGROUND TO THE INVENTION

Conventional presses used for pressing bales are column-type presses.These presses include two opposing platens moveable relative to oneanother to press a bale between the opposing faces of the platens. Anumber of columns extend between the two platens, the number usuallybeing four with the columns symmetrically arranged on either side of thepress. The considerable stresses associated with the pressing force aretransferred through the columns. Therefore the bale should be presentedaccurately to the press. Any misalignment could cause serious imbalanceto the columns, the likely result being cracking of the press columns orthe frame of the press.

Conventionally, bales are presented to the press by an endless beltconveyer. The belt runs over the top of one of the platens defining thepress table and down through an opening under the table. The inheritdifficulty with this arrangement is that as a bale is compressed by thepress, this action tends to stretch the belt and so cause rapid wearingof the belt. If the belt joint should lie within the press duringpressing, considerable stress will be placed on the joint. This leads toinevitable breaking of the belt involving substantial down time while anew belt is fitted and tracked.

It is therefore an object of the present invention to provide a pressingassembly and/or a method of pressing which overcomes or ameliorates thedisadvantages referred to above or provides the public with a usefulchoice.

SUMMARY OF THE INVENTION

In accordance with a broad aspect of the present invention there isprovided a pressing assembly including a press being moveable from anopen configuration to an operable configuration to compress an object,and a loading means having one or more pushers moveable into a regionwithin the press to load the object to a pressing zone within the press,the arrangement being such that the or each pusher is clear of thepressing zone once the press is in the operable configuration.

Preferably there are two pushers arranged to act on opposite sides ofthe object. The pushers may be retractable to move past a subsequentobject to be loaded. Preferably the assembly also includes ejectionmeans.

In accordance with a second aspect of the present invention there isprovided a pressing assembly including a press for pressing objects, aloading/unloading means for loading objects into and out of the press,the loading means including a reciprocable pusher assembly moveable in aforward and a reverse direction, the pusher assembly having a firstpusher moveable with the pusher assembly for loading one of said objectsto a pressing zone in the press on forward movement of the pusherassembly, a second pusher moveable with the pusher assembly for ejectinganother of said objects from the pressing zone on forward movement ofthe pusher assembly wherein, in the reverse direction of the pusherassembly, the second pusher is moveable to retract beyond the objectloaded into the pressing zone.

Preferably the reciprocal pusher assembly includes a linkage enablingthe first and second pushers to move in unison. It is preferred that thelinkage is a rail. This construction enables the rail to slide linearlyalong a support frame. The linkage, eg the rail, with the first andsecond pushers may be disposed to the side of the path of objects beingloaded into the press.

Suitably the reciprocal pusher assembly is such to load objects one byone into the press. Alternatively, bundles or groups of objects may beloaded into the press although the preferred intended application is foruse with pulp bales.

In a most preferred form of the invention there are two rails disposedon either side of the path of the objects being loaded into the press,each including first and second pushers. It is preferred that the tworails are joined so as to move in unison thereby defining a moveablecarriage. This enables the carriage to be reciprocated by a singlereciprocating means such as an hydraulic cylinder.

As mentioned above, the preferred means of moving the reciprocablepusher assembly is by an hydraulic cylinder. However, other arrangementseg using cams, rack and pinion are also considered within the scope ofthe present invention.

As mentioned above, the reciprocable pusher assembly may be slidablerelative to a support frame. In a preferred form of the invention thisincludes a track with gliders extending from the reciprocable pusherassembly received within the track. The support frame may be erectedindependently next to the press. Alternatively, one end of the supportframe may be supported by the press.

Preferably, the press includes opposing horizontal platens moveablerelative to one another. Suitably, but not exclusively, one platen isstationary while the other moves. The base of the objects it transversesthe path through the loading/unloading means towards the press defines aloading plane. Preferably, the stationary platen is level with theloading plane. Suitably, the press operates to close in a directionorthogonal to the loading plane. The press is preferably a column typepress.

Suitably, the reciprocable pusher assembly is such that it does notinterfere with the operation of the press during the closing of theplatens. The reciprocable pusher assembly may be completely free of theplatens prior to any closing of the press. Alternatively, the press mayoperate to initially apply a minimal pressure to the object within thepress to thereby hold the object in the pressing zone so as to minimisethe possibility of movement when the reciprocable pusher assembly ismoved in the reverse direction. The reciprocable pusher assembly maymove into the space between the opposing platens once the platens haveopened sufficiently to enable a subsequent object to be loaded into thepress. Alternatively, the reciprocable pusher assembly may be completelyfree of the press until the platens are fully open.

The second pusher operating as an ejection pusher may be pivotable. Inan alternative form of the invention, the second pusher may simplyreciprocate for example at 90° to the direction of movement of thereciprocable pusher assembly. For example, a reciprocable pusher mayinclude a curved surface which, when making contact with an object inthe pressing zone cause the pusher to retract inwardly. As anotheralternative, rollers may be incorporated to assist with retraction ofthe second pusher.

In a most preferred form of the invention, there are two second pusherson either side of the path of the objects moving towards the press eachbeing elongate in the form of fingers.

Preferably, the second ejection pushers are biased to return to theunretracted configuration once past the pressing zone to return thesecond pushers to a configuration adapted to eject an object from thepress. A spring may form a suitable bias to the second pusher.

The pusher may be moveable to retract out of the pressing zone by simplecontact with the object in the pressing zone. For this reason, it ispreferred that the biasing means biasing the second pusher to theunretracted configuration has a lesser effect than the force resistingmovement of the object from the pressing zone. This will ensure that thesecond pusher does not inadvertently disturb the object in the pressingzone on its reverse movement with the reciprocable pusher assembly. Inan alternative form of the invention, the second pusher may be trippedto automatically retract when moving past the pressing zone.

Preferably the first pusher moves an object from a loading zone to thepressing zone. In a similar fashion to the second pusher, the firstpusher may be moveable relative to the reciprocable pusher assemblyduring the reverse direction of the pusher assembly, to retract beyondthe loading zone. The first pusher may therefore possess any of thefeatures described above in connection with the second pusher.

The pressing assembly further includes a conveying means to conveyobjects to the loading zone. The conveying means may be aligned with theloading plane along which the objects move on their path to the press.In an alternative form of the invention, the conveying means may conveythe objects from above or below or from either side. Preferably theconveying means is a belt conveyer.

In accordance with a third broad aspect of the present invention thereis provided a method of loading objects into a press having two opposingplatens, the method including using one or more pushers to load theobject to a pressing zone within the press whereby the pushers are clearof the pressing zone once the press operates to compress the object.

In accordance with a fourth aspect of the present invention there isprovided a method of loading/unloading objects into a press, the methodincluding using a reciprocable pusher assembly having first and secondpushers, moving the reciprocable pusher assembly in a forward directionto simultaneously move both the first and second pushers such that thefirst pusher moves one of said objects to a pressing zone in the pressand the second pusher ejects another of said objects from the press,moving the reciprocable pusher assembly in a reverse direction tosimultaneously move both the first and second pushers wherein the secondpusher also moves to retract beyond the pressing zone.

This invention may also be said broadly to consist in the parts,elements and features referred to or indicated in the specification ofthe application, individually or collectively, and any or allcombinations of any two or more said parts, elements or features, andwhere specific integers are mentioned herein which have knownequivalents in the art to which this invention relates, such knownequivalents are deemed to be incorporated herein as if individually setforth.

The invention consists in the foregoing and also envisages constructionsof which the following gives examples only.

BRIEF SUMMARY OF THE DRAWING

In order that the invention may be more fully understood, one embodimentwill now be described by way of example with reference to the followingdrawings in which:

FIG. 1 is a perspective view of a pressing assembly in accordance with apreferred embodiment of the present invention;

FIG. 2 is an end view of a portion of the pressing assembly shown inFIG. 1 and

FIG. 3 is a plan view of the pressing assembly shown in FIG. 1.

BEST MODE FOR CARRYING OUT THE INVENTION

As shown in FIG. 1, the pressing assembly 10 includes a press 12 and aloading/unloading means 14 for loading and unloading objects 16 into andout of the press 12. The objects 16 travel over a support surface whichcould be in the form of a metal plate (not shown).

The press 12 comprises opposing platens 20, 22, one of which isstationary to define a pressing surface or press table 24. The otherplaten is moveable to compress an object 16 placed between the opposingplatens 20, 22. The moveable platen 22 slides relative to the fourcolumns 28 of the press 12, there being two columns one each side of thepress 12.

The press table 24 supports one end of a support frame 32 forming partof the loading/unloading means 14. As shown in FIG. 3, the support frame32 is shaped with four circular recess 29, each to receive a column 28of the press 12. This enables the support frame 32 to fit within thepress 12. The support frame 32 is supported at the other end by uprightsupport 34. The support frame 32 provides a guide for a reciprocablepusher assembly in the form of a slidable carriage 36 reciprocated backand forth along the frame by a hydraulic cylinder 40. The cylinder 40 ispowered by a simple powerpack (not shown) incorporating a pump,directional control valve and a relief valve. In another preferred formof the invention, the carriage may be driven by a vari-speed electricmotor, connected to the carriage by a chain drive.

The slidable carriage 36 is defined by a pair of spaced rails 38 and byrespective uprights 39 joined at their ends to respective outer ends ofthe rails 38, as well as a cross bar 50 joining the opposite ends of theuprights 39. Each of the spaced, parallel rails 38 are supported byrespective sides of the support frame. The rails 38 which aresubstantially horizontal as shown are slidable relative to therespective sides of the support frame 32. It will be apparent that therails 38 are slidable into the region defined by the two opposingplatens of the press.

As shown most clearly in FIG. 2, the support frame 32 is comprised of alower plate 33. Spaced support brackets 35 are secured to the lowersupport plate 33 at spaced locations there along. Both the lower supportplate 33 and the spaced support brackets 35 support respective lengthsof angle section 37. The angle sections 37 on each side of the supportframe 32 define a space therebetween. The angle sections 37 are orientedwith their 90° angles facing away from the space therebetween.

The spaced rails 38 of the slidable carriage 36 each include a number ofrollers 41 each having a shape complementary to the space between theangle sections 37. The rollers roll along the lower angle section 37 andare retained in position by the upper angle section 37.

The slidable carriage 36 also includes a pair of first pushers 42 in theform of elongate fingers pivotally attached about a vertical axis torespective rails 38. It will be apparent from the figure that as thecarriage 36 is slid towards the press, the fingers 42 act against thetailing side of the object 16 to push the object into the region betweenthe two platens. In this way, the object 16 can be relatively accuratelypositioned between the two platens and the region between the platens tobe occupied by the object is referred to as “the pressing zone”. Theaccurate positioning in the centre of the press ensures that the loadthrough the press columns is balanced for longevity of the press.

As the object 16 is moved into the pressing zone, a subsequent object ismoved into the loading zone previously occupied by object 16 in thefigure. This subsequent object may be moved into this position by meansof a conventional conveyer. In order that the fingers 42 may move pastthe subsequent object in the loading zone so as not to push it out ofthe loading zone away from the press, the fingers 42 are pivotable. Onreverse motion of the slidable carriage 36 the sides of the fingers 42will contact the object and be retracted away from the object andtowards the respective rails 38 of the carriage 36. In this way, witheach forward motion of the carriage 36 an object is moved from theloading zone to the pressing zone between the platens. On each reversemotion of the carriage 36 the fingers 42 retract as they pass thesubsequent-object in the loading zone. The fingers 42 are biased toreturn to the extended configuration illustrated in FIG. 3. Further, astop is provided to define the extended configuration. It can be seenthat in this position, the end face of the fingers 42 extends at 90degrees to the direction of travel of the carriage 36.

The slidable carriage 36 also includes a pair of second pushers 44. Thesecond pushers 44 are of a similar construction to the first pushers 42and comprise pivotable fingers which are biased to return to theextended configuration defined by the stop 43. The second fingers 44perform the function of ejecting an object from the pressing zone of thepress 12 with each forward motion of the sliding carriage 36. Onrearward motion of the sliding carriage 36, the second fingers 44 areretractable so as to move past the object in the pressing zone withminimal disruption to its positioning.

Proximity switches (not shown) locate the bale correctly at the pressingzone. This forms part of a control system to ensure that the bale isproperly located at a central position within the press. Furtherproximity switches can be used to detect and/or indicate that theslidable carriage has moved out of the region between the two platens20, 22.

The foregoing describes only one embodiment of the present invention andmodifications may be made thereto without departing from the scope ofthe present invention.

What is claimed is:
 1. A pressing assembly comprising: press forpressing objects; and means for loading objects into and out of thepress, wherein the means for loading is operatively connected to thepress and comprises a reciprocable pusher assembly moveable in a forwardand a reverse direction, the pusher assembly comprising: a first pushermoveable with the pusher assembly for loading one of said objects to apressing zone in the press on forward movement of the pusher assembly;and a second pusher moveable with the pusher assembly for ejectinganother of said objects from the pressing zone on forward movement ofthe pusher assembly wherein, in the reverse direction of the pusherassembly, the second pusher is moveable to retract beyond the objectloaded into the pressing zone.
 2. The pressing assembly as claimed inclaim 1 wherein the reciprocal pusher assembly includes a linkageenabling the first and second pushers to move in unison.
 3. The pressingassembly as claimed in claim 2 wherein the linkage is a rail.
 4. Thepressing assembly as claimed in claim 3 wherein the reciprocable pusherassembly is supported by a support frame, and the rail is slidablelinearly along the a support frame.
 5. The pressing assembly as claimedin claim 4 wherein gliders extend from the reciprocable pusher assemblyand the support frame includes a track, the gliders being receivedwithin the track.
 6. The pressing assembly as claimed in claim 4 whereinone end of the support frame is supported by the press.
 7. The pressingassembly as claimed in claim 2 wherein the linkage, with the first andsecond pushers, is disposed to the side of the path of the objects beingloaded into the press.
 8. The pressing assembly as claimed in claim 7wherein there are two linkages disposed on either side of the path ofthe objects being loaded into the press, each including first and secondpushers.
 9. The pressing assembly as claimed in claim 8 wherein the twolinkages are joined so as to move in unison thereby defining a moveablecarriage.
 10. The pressing assembly as in claim 9 wherein the carriageis reciprocated by a single reciprocable means for driving.
 11. Thepressing assembly as claimed in claim 1 wherein the reciprocal pusherassembly is such as to load individual bales sequentially into thepress.
 12. The pressing assembly as claimed in claim 1 wherein the presscomprises opposing platens which close to compress one or more of saidobjects loaded into the pressing zone within the press and thereciprocable pusher assembly is such that it is clear of the pressingzone during the closing of the platens.
 13. The pressing assembly asclaimed in claim 12 wherein the reciprocable pusher assembly iscompletely clear of the region between the platens prior to any closingmovement of the press.
 14. The pressing assembly as claimed in claim 12wherein the press operates to initially apply a minimal pressure to theobject within the press to thereby hold the object in the pressing zoneso as to minimise the possibility of movement when the reciprocablepusher assembly is moved in the reverse direction.
 15. The pressingassembly as claimed in claim 12 wherein the reciprocable pusher assemblyis operable to move into the space between the opposing platens once theplatens have opened sufficiently to enable a subsequent one of saidobjects to be loaded into the press.
 16. The pressing assembly asclaimed in claim 12 wherein the reciprocable pusher assembly is operableso as to be completely free of the press until the platens are fullyopen.
 17. The pressing assembly as claimed in claim 1 wherein the oreach second pusher is pivotable.
 18. The pressing assembly as claimed inclaim 1 wherein the or each second pusher is in the form of an elongatefinger.
 19. The pressing assembly as claimed in claim 1 wherein the oreach second pusher is biased by a means for biasing to return to theunretracted configuration.
 20. The pressing assembly as claimed in claim19 providing a plurality of second pushers which are moveable duringreverse movement of the pusher assembly to retract out of the pressingzone by simple contact with the object in the pressing zone wherein themeans for biasing which bias the second pushers to the unretractedconfiguration has a net effect of which is less than the force resistingmovement of the object from the pressing zone.
 21. The pressing assemblyas claimed in claim 1 wherein the or each first pusher is operable tomove an object from a loading zone to the pressing zone in the forwarddirection of the pusher assembly with the or each first pusher beingretractable in the reverse direction of the pusher assembly to retractbeyond a subsequent one of said objects positioned in the loading zone.22. The pressing assembly as claimed in claim 21 wherein the or eachfirst pusher is biased to return to the unretracted configuration. 23.The pressing assembly as claimed in claim 1 wherein the or each firstpusher is pivotable.
 24. The pressing assembly as claimed in claim 1wherein the or each first pusher is in the form of an elongate finger.25. A method of loading/unloading objects into a press, the methodcomprising: moving a reciprocable pusher assembly in a forward directionto simultaneously move both first and second pushers thereof such thatthe first pusher moves one of said objects to a pressing zone betweenopposing platens in the press and the second pusher ejects another ofsaid objects from the press; and moving the reciprocable pusher assemblyin a reverse direction to simultaneously move both the first and secondpushers wherein the second pusher also moves to retract beyond thepressing zone.
 26. The method as claimed in claim 25 wherein thereciprocable pusher assembly is movable to slide along a support frame.27. The method as claimed in claim 25 wherein the reciprocable pusherassembly loads the objects sequentially into the press.
 28. The methodas claimed in claim 25 wherein the reciprocable pusher assembly is suchthat it is clear of the pressing zone during closing of the platens. 29.The method as claimed in claim 25 wherein the press operates toinitially apply a minimal pressure to the object within the press tothereby hold the object in the pressing zone so as to minimise thepossibility of movement when the reciprocable pusher assembly is movedin the reverse direction.
 30. The method as claimed in claim 25 whereinthe reciprocable pusher assembly is operable to move into the spacebetween the opposing platens once the platens have opened sufficientlyto enable a subsequent object to be loaded into the press.
 31. Themethod as claimed in claim 25 wherein the reciprocable pusher assemblyis operable so as to be completely free of the press until the platensare fully open.
 32. The method as claimed in claim 25 wherein the oreach second pusher pivots to retract beyond the pressing zone.
 33. Themethod as claimed in claim 25 wherein the or each second pusher isbiased to return to the unretracted configuration.
 34. The method asclaimed in claim 25 wherein the or each first pusher operates to move anobject from a loading zone to the pressing zone in the forward directionof the pusher assembly with the or each first pusher retracting in thereverse direction of the pusher assembly to retract beyond a subsequentobject positioned in the loading zone.
 35. The method as claimed inclaim 25 wherein the press includes one stationary platen and onemovable platen, and wherein the base of the object as it is moved by thereciprocable pusher assembly towards the press defines a loading plane,the stationary platen being level with the loading plane.
 36. A methodof loading objects into a press having two opposing platens, the methodcomprising: providing an object to a be pressed; and using a loadercomprising one or more first pushers movable within a region between theplatens to load the object to a pressing zone within the press wherebythe pushers are clear of the pressing zone once the press operates tocompress the object; and simultaneously with the loading step, using anejector comprising one or more second pushers to eject a precedingobject from within the press, the second pushers being retractable tomove past the object loaded into the press.
 37. The method as claimed inclaim 36 wherein there are two first pushers arranged to act on oppositesides of the object.
 38. The method as claimed in claim 36 wherein thefirst pushers retract to move past a subsequent object to be loaded. 39.The pressing assembly as claimed in claim 1 further comprising means fordetecting accurate placement of the object being loaded at the pressingzone.
 40. The method as claimed in claim 25 further comprising using adetector to accurately place the object being loaded at the pressingzone.